Push-push circuit breaker



JanQZZ, 1963 E. T. PLATZ ETAL PUSH-PUSH CIRCUIT BREAKER 5 Sheets-Sheet 1 Filed Dec. 17, 1959 INVENTORS ELM 000 f PLJTZ BY wrrme M/TCH/V/CK Jan. 22, 1963 E. T. PLATZ ETAL 3,075,058

' PUSH-PUSH CIRCUIT BREAKER Filed Dec. 17, 1959 5 Sheets-Sheet 2 EJB.

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PUSH-PUSH CIRCUIT BREAKER Filed Dec. 17, 1959 5 Sheets-Sheet 3 is: 53.5 a.

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INVENTORS 4 W000 r P1472 United States Patent M 3,i5,tl5 PUSH-PUEH Qiltflllill BREAKER Elwood ll. Flats and Victor Mitehnick, Detroit, Mich, as-

siguors to li-T-E Eircuit Breaker Company, Philadelphia, Pa, a corporation or Pennsylvania Filed Dec. 17, 195?, her. No. 860,273 25 Qiairns. (tll. ass-es The instant invention relates to circuit breakers of the type utilized for the protection of branch circuits in the home and for light industrial applications. More particularly, the instant invention relates to a circuit breaker, of the type previously noted, which is manually operated between its On and Off positions by successive operations of a slidable handle in the same direction.

in US. Patent 2,385,727 there is illustrated a single pole circuit breaker of the so called push-push type. In order to conserve panel board space the instant invention provides a construction which is so compact that two single pole units now occupy the space formally occupied by the single pole unit of the aforesaid Patent 2,385,727. The compact construction is achieved without sacrificing any of the features found in large size breakers of this type.

That is, the breaker of the instant invention achieves a slow make through the long stroke of the manual operating handle in moving to the On position. Quick break is achieved by tripping a latch through a short stroke of the operating handle to the (3ft position. Automatic resetting is achieved during the long stroke of the handle to the On position. The mechanism is trip free and there is a magnetic coil for instantaneous tripping at predetermined low values of overload current as well as under short circuit conditions. There is a dual On-0it indication achieved by having the manual operating handle occupy diiierent positions for the On and Off conditions of the breaker and also having a visible member which carries On-Oil indicia thereon.

The above noted features are achieved with a construction utilizing tWo sub-assemblies which are readily insertable into a molded plastic case. This construction facilitates assembly, renders the mechanism immune to expansion contraction or deterioration of the plastic case, and permits electrical calibration of the trip means outside of the case before final assembly.

One sub-assembly comprises the manuual operating handle and a tripping pawl while the other sub-assembly comprises all of the moving parts of the circuit breaker not carried by the handle such as the movable contact arm, the time delay tripping means and the instantaneous tripping means.

Accordingly, a primary object of the instant invention is to provide a novel construction for a circuit breaker of the push-push type.

Another object is to provide a novel circuit breaker of especially compact and inexpensive construction.

Still another object is to provide a circuit breaker contruction whereby two single pole units occupy the same space in a panelboard occupied by a single pole unit of the prior art.

A further object is to provide a novel circuit breaker construction comprised of two sub-assemblies insertable into a molded plastic case.

A still further object is to provide a novel circuit breaker sub-assembly which includes a movable contact, a bimetallic trip means and a coil for instantaneous tripping at predetermined low values of overload current as well as under short circuit conditions.

These as well as other objects of the instant invention shall become readily apparent after reading the following description of the accompanying drawings in which:

FIGURE 1 is a pers ective with the back cover removed, constructed in accordance with the instant invention. The case is constructed to house two individual pole units. However, only a single pole unit is illustrated.

FIGURE 1:; is a plan view of the circuit breaker oi FIGURE 1.

FIGURE 1b is a back view of the circuit breaker case illustrated in FIGUQE l with the mechanism removed so that internal details of the case are visible.

FIGURE 2 is a cross-section taken through line 2-2 of FIGURE 2a looking in the direction of the arrows. In FIGURE 2 the mechanism is in the circuit closed position.

FIGURE 2a is a rear elevation of the circuit breaker, with the cover removed, looking in the direction of arrows 2a2a of FIGURE 2.

FIGURE 3 is a view similar to FIGURE 2 with the mechanism in the circuit open position.

FIGURE 4 is a side elevation of the electrical subassembly.

FEGURES 4a and 4b are cross-sections taken through lines 4a4zz. and lb-41), respectively, of FEGURE 4 looking in the directions of the respective arrows.

FIGURE 5 illustrates a modified mounting for the bimetal time relay tripping means which incorporates features for ambient compensation.

FIGURE 6 is a side elevation of the handle sub-assembly.

FIGURE 6.4 is an end view of the handle sub-assembly looking in the direction of arrows 6a-6a of FZGURE 6.

HGURE 7 is a cross-section taken through lines 7-7 of FIGURE '70: looking in the direction of the arrows and illustrates a modified circuit breaker construction.

FIGURE 7a is a back view of the circuit breaker of FEGURE 7 with the cover removed to reveal details of the operating mechanism.

Now referring to the fi ures and more particularly to FIGURES 1-641, each pole of duplex circuit interrupter res comprises a case Iii-ll, molded of insulating material, wherein electrical sub-assembly iii). (EEGURES 44b) are disposed in operating relationship. Since the operating mechanisms for both poles of duplex circuit interrupter see are identical, only one pole unit shall be described in detail.

The current path through each pole of the interrupter is from line terminal ii, its stationary contacts lb, movable contact 252, contactor arm 2, pigtail 3, bimetal support t, bimetal 5, pigtail 6, coil 7, load terminal tang S, and load terminal collar 9. The case lot is provided with three slots Ittla for receiving rivets it which secure cover it and cover liner 5.2 t case till. Duplex breaker ltitl is attached to the mounting plate of the ultimate enclosure by means of the lugs 111a formed from the cover it. A case aperture lt b is provided through which the reduced portion to of line terminal 1 extends to the outside of the case hill where line terminal screw 13 is positioned by screw retainer 14. Case Elli. includes hole the through which coir end "in extend at the point where it is attached to the tang 8.

The upper part of the case it has two substantially identical cavities lilld and lite defined by the outside walls 1th and Mg and a centrally located wall iii/z the ends of which provide walls llli which form openings or guides for the upper portion of handle l5. Post i i/c with its circular projection Iiils comprise means for positioning frame id in case till. Curved grooves than comprise means for operating the On and Off indicator as will be hereinafter explained. A contact chamber ltin in the lower part of case 101 receives line terminal 1 with its two contacts lb. The grooved opening tilt receives vent screen Hi5.

view 01 a circuit breaker,

Tang 8 has a circular embossment 8a which acts as a supplementary holding means for the load terminal conductor (not shown) and which cooperates with the spherical end 16a of load terminal screw 16 to draw tang 8 out of ease Th1 and the collar inward. .End 8b of tang 8 is bent down to hold the collar 9 in place.

Handle sub-assembly 1% comprises pawl device 17 pivotally mounted to handle 15 by shoulder rivet 18. The combination compression and torque spring 19 holds the pawl 17 against the handle surface llSaand at the same time biases pawl 17 in a clockwise direction for a purpose to be explained later. The pawl 1'7 includes a notch 1%, a flange 17a, a hook 170, and an armature engaging lug 1741, for purposes to be explained later. The groove 15b slidably receives the On-Otf indicator plate lltl'7 which is visible through an opening in the projection 50 on handle 15 and which is moved into its On and Off positions by its lug 1% which rides in groove lltlm of case 101.

Pocket 15a is a recess for the handle return spring 26. This spring also extends partly into a similar pocket lllp in case ltl'll. One end of handle return spring 26 rests against the lug lttq in the case 161 while the other end of spring 2% bears against surface 156 of handle 15 so that the handle 15 is always biased outwardly, for a reason to be explained later. The sloped surface 15 of handle 15 is the resetting surface for contactor arm 2.

Frame 16 includes flange ltia with a hole 16b which locates the shoulder guide rivet 29 which in turn is the pivot point for the arm 2. The embossment 16c locates the upper end of the main spring 21. Flange 16d has a hole at Me for receiving shoulder rivet 22. The flange 16 has 2 rivet holes for the attachment thereto of the bimetal support 4. The upwardly bent flange 16g has notches 1611 on both sides to receive the lugs 24a on the end of the bent portion 24b of armature 24- to form a tongue and groove connection between these members. The embossment 161 located between the notches 16h is for the purpose of providing a frictionless bearing for the lower end of armature 24. End 16g is bent upward 45 so that armature 24 will always be biased downwardly to a uniform and consistent position. The lower end of bimetal is attached to the lower end of bimetal support 4 while the upper end of bimetal 5 deflects to the left to engage the insulated rivet 2d of armature 24 to trip the breaker thermally, by means to be described later.

Contactor arm 2 is provided with movable contact 2b at the left end and an elongated slot 20 having clearance at 2d to provide clearance for contact wear and clearance at 22 so that the arm 2 can be raised when reset. The surface 2 of arm 2 is for resetting while the bent end 2g is for engagement with the latch edge 24d of armature 24. Arm lug Zj receives the lower end of the mainspring 21. Offset 2k clears the edge 16s on the frame 16 during the normal operation of arm 2 but during pre-assembly or calibration, it limits the movement of arm 2 so that spring 21 will not fly off. This feature will be explained more completely later.

Armature 24 includes a clearance slot 241) to receive the shoulder portion 22a of shoulder rivet 22, a hole 240 for the insulating rivet 26, and a latch surface 244 for engaging the latch 2g of arm 2 as previously mentioned. The hook 24s is the manual off lug which engages pawl surface lZ b, to be explained later. Head 2217 of rivet 22 acts as a stop for the armature 24 against the reaction of conical spring 27. Shoulder 22a retains magnetic core 2% in the position shown with coil 7 of several turns positioned around magnetic core 28.

From the preceding description of the mechanism, it should be apparent that contactor 2, under the influence of spring 21, can be unlatched from armature 2a to assume the Ofi position of FIGURE 3 by three methods as follows. Manually, by means to be explained more fully later, the surface 17d of pawl device 1'7 engages hook 24a Thermally, the top of bimetal 5 warps-to the left with respect to FIGURE 2 under moderate conditions of overload to engage the insulating rivet 26. When the current reaches a high value of overload, the magnetic ilux generated by coil '7 draws the top of the armsture 24 instantly to the left, likewise to cause unlatching.

For the mode of operation, reference is first made to the Off position of FIGURE 3 where pawl 1'7 'is shown held in its extreme counterclockwise position by the latch surface 2.]: on the bent end 2g of arm 2 bearing against flange 17a of pawl 17. When handle 15 is depressed, its cam surface 15 engages the cam surface 2 of arm 2 causing latch surface 2;; to rise and ultimately to latch or to rest on the latch surface 24d of armature 24. The relation between the cam surfaces 151 and 2] is such that arm 2 does not rise until the armature engaging lug 17d of pawl 1'7 is under the hook 24a of armatureza so that handle 15 is not stopped in an intermediate position by the engagement of these elements.

During the later portion of the inward travel of the handle 15, the bent end 2g of arm 2 has moved away from flange 17a which now rides along the under side of hook 2% under the clockwise influence of spring 19. When handle 15 is released from the full inward position of its On stroke, it is biased to the right by handle return spring 20 and latch edge 211 of arm 2 pivots on latch edge 24d of the armature 24. The arm 2 under the influence of mainspring 21 is biased in a counterclockwise direction causing firm engagement between contacts 2b and 1b. Also during this outward movement of handle 15, armature engaging lug 17d disengages from armature hook 24c permitting pawl 17 under the influence of spring 19 to rotate clockwise causing hook 17c to engage lug 16m thereby limiting the outward travel of handle 15 to its On position as shown in FIGURE 2.

Means to provide two positions of a handle corresponding to the On and'Ofi conditions of the breaker through the cooperation of pawl tip 17c and frame lug 16m has been described. An additional means of On and Off indication is given by indicia carrying plate 1% sliding in the groove 15b of the handle guided by case groove 10m. To turn the breaker Off, handle 15 is depressed from the On position of FIGURE 2 so that armature engagement lug 17d of pawl 17 engagesthe bight in the armature hook 242 and rotates armature 24 in a counterclockwise direction about its lower end causing the upper end to move to the left against the bias of the conical armature return spring 27. This causes latch 24a of armature 24 to unlatch from latch edge 2h of contactor 2 and permits contactor 2 under theinfluence of main spring 21 to pivot about the shoulder guide rivet 29 and to rotate clockwise into the Off position of FIGURE 3. This sequence of movement also causes the bent end 2g of arm 2 to strike and depress the flange 17a of the pawl 17 causing the hook 17c to disengage from the lug 16m, whereupon handle 15 under the influence of handle return spring 2%), will move to the right into the Off position.

The purpose of the bight in the hook 24c is to obtain a positive stop for lug 17d and likewise for handle 15 so that, if handle 15 is depressed excessively, lug 17:! will not slip off hook 24c. 'If the lug could slip off hook 242, the operator could inadvertently turn the breaker Off and immediately turn. it On again'during the supposedly Ofi-On stroke of handle 15. The bight in hook 242 will force the operator to at leastslightly release the handlein turning Ofi before he can push handle 15 all the way in to turn the breaker On. It should be noted here that considerably more inward movement of handle 15, is required to turn the breaker On than is required to turn the breaker Off.

The Ofi position of FIGURE 3 showsno interference between offset 2 k in arm 2 and the edge 16s of frame 16. It is apparent, that during preassembly with pawl 37 and handle 15 not in place, the space relation be tween offset 2!: and edge 16s will limit excessive clockwise movement of arm 2 and consequently prevent the mainspring 21 from flying into space.

The trip free feature is accomplished as follows: With reference to the On position of FIGURE 2, it has been explained that when handle is depressed, armature engagement lug lld of pawl 17 engages armature hook 24a to unlatch the latch surface 2g of arm 2 from latch surface 2 of the armature 24. It is obvious that this action is an aid rather than a deterrent to the movement of armature 2d when the upper end of bimctal 5 deflects to the left under conditions of moderate overload or when the armature 24 is magnetically drawn to the left under conditions of high values of overload. It is also obvious that cam surface 2f of arm 2, moves away from cam surface 15 of handle is when the breaker is unlatched either manually, thermally by the bimetal, or magnetically by the coil.

PEGURE 5 shows an alternate embodiment providing ambient compensation. Here the bimetal support do for the main bimetal 5 is also comprised of bimetal having ib as the high expansion side. The deflection of the top of the bimetal 5 to the left due to an increase in ambient temperature is compensated for by the clockwise movement of the lower end of the bimetal support i a due to the same increase in ambient temperature.

FIGURE 7 shows the Sn position or" another embodiment of this invention employing the same contactor arm and very much the same handle sub-assembly but with a diliercnt load terminal, bimetal mounting, armature and coil arrangement. in this construction, the frame 15 as an assembly chassis is not used but generally the parts of the mechanism are installed individually and directly into the case. The lower end .0a of bimetal so is attached directly to load terminal 41. The lower end 42:: of flexible metal tripper 42' is secured to the lower portion of bimctal lil and has a latch plate 43 of insulating material attached to its upper end. U-shaped magnetic yoke 47' is attached to bimetal 46 at 47a and has a hole 472; for slidably receiving the right hand end 44:; of cylindrical magnetic plunger 4d. The plunger tip 48, of non-magnetic material slidably extends through a hole in bimetal as and engages the right hand side of latch plate 43.

A coil of several turns of insulated conducting wire is mounted inside of yoke 4-7 and loosely surrounds plunger 4-4. This coil is not shown except that one end is attached to the bimetal at a and the other end is connected to the arm 2 at 2b by means of a pigtail as to complete the circuit from the load terminal ll to the line terminal 1. In the On position shown, the latch edge 271 on the under side of the bent end 2g of the arm 2 previously described rests on the latch edge lfla of the latch plate 43.

Similar in action to the embodiment, the engagement between latch edge 2g of the arm 2 and the latch edge 63a will be unlatched when handle 15 is advanced in causing the lug 17d on pawl 17 toengage the bottom edge idb of latch plate Contactor 2 will then pivot about the stationary pin t? and rotate in a clockwise direction into the Oil position. This unlatching between the latch edge 2h and the latch edge 43 will also occur when the top bimetal dd warps to the left under conditions of light overload or when magnetic plunger as is drawn to the left instantly under conditions of heavy overload. The turning on movement is similar to that of the embodiment previously described.

Thus, we have provided a novel construction for a pushpush type circuit breaker. The construction is especially compact and is of a nature such that all calibration may be accomplished while the trip units are outside of the circuit breaker housing before final assembly of the interrupter.

Although we have here described preferred embodiment of our novel invention, many variations and modifications will now be apparent to those skilled in the art, and

we therefore prefer to be limited, not by the specific disclosure herein, but only by the appending claims.

We claim:

1. A circuit interrupt r comprising a handle arranged to be advanced manually and returned automatically, means for automatically returning the handle, a stop for limiting return movement of and defining an extreme position of the handle; a cont actor carrying a movable contact movable through manual advance of said handle, a pawl device movably mounted to said handle for limiting return movement of the handle to an intermediate position, the pawl device movable into and out of handle stopping position, means biasing said pawl device into handle stopping position, said contactor in moving to circuit open position operating said pawl device against its bias out of handle stopping position and permitting movement of tr e handle to the extreme position.

2. A circuit interrupter comprising a handle arranged to be advanced manually and returned automatically, means for automatically returning the handle, a stop for limiting return movement of and defining extreme position of the handle; a contactor carrying a movable contact movable through manual advance of said handle, a pawl device movably mounted to said handle for limiting return movement or" the handle to an intermediate position, the pawl device movable into and out of handle stopping position, means biasing said pawl device into handle stopping position, said con-tactor in moving to circuit open position operating said pawl device a ainst its bias out of handle stopping position and permitting movement of the handle to the extreme position, a stationary contact engageable by said movable contact, latch means engagcable with said contactor and when so engaged permitting operation of said contacts into engagement, said latch means when disengaged from said contactor preventing said contacts from remaining in and being brought into engagement, said pawl device having a portion engageable with said latch means for tripping thereof upon advancement of said handle from said intermediate position while said pawl device is in said hanle stopping position.

3. A circuit interrupter comprising a handle arranged to be advanced manually and returned automatically, means for automatically returning the handle, a stop for limiting return movement of and defining an extreme position of the handle; a contactor carrying a movable contact movable through manual advance of said handle, a pawl device movably mounted to said handle for limiting return movement of the handle to an intermediate position, the pawl device movable into and out of handle stopping position, means biasing said pawl device into handle stopping position, said cont-actor in moving to circuit open position operating said pawl device against its bias out of handle stopping position and permitting movement of the handle to the extreme position, a stationary contact engageable by said movable contact, latch means engagea le with said contactor and when so engaged permitting operation of said contacts into engagement, said latch means when disengaged from said contactor preventing said contacts from remaining in and being brought into engagement, said pawl device having a portion engageable with said latch means for tripping thereof upon advancement of said handle from said intermediate position while said pawl device is in said handle stopping position, a time delay tripping means comprising a bimetal elem nt engageable with said latch means for tripping thereof.

4. A circuit interrupter comprising a handle arranged to be advanced manually and returned automatically, means {or automatically returning the handle, a stop for limiting return movement of and defining an extreme position of the handle; a cont-actor carrying a movable contact movable through manual advance of said handle, a pawl device movably mounted to said handle for limiting return movement of the handle to an intermediate sermons position, the pawl device movable into and out of han dle stopping position, means biasing said pawl device intohandle stopping position, said contactorin moving to cir-- .cuit open position operating said pawl device against its. bias out of handle stopping position and permitting move-- ment of the handle to the extreme position, a stationary contact engageable by said movable contact, latch means engageable with said contactor and when so engaged per mitting operation of said contacts into engagement, said. latch means when disengaged from said contactor pre' venting said contacts from remaining in and being: brought into engagement, said pawl device having a por-- tion engageable with said latch means for tripping thereof upon advancement of said handle from said intermediate position while said pawl device is in said handle stopping: position, a time delay tripping means comprising a bimetal element engageable with said latch means for trip-- ping thereof, an instantaneous tripping means compris ing a coil operatively positioned to have a magnetic field. generated by current flowing in said coil embrace said latch means for tripping thereof.

5. A circuit interrupter comprising a handle arranged to be advanced manually and returned automatically, means for automatically returning the handle, a sto for" limiting return movement of and defining an extreme: position of the handle; a contactor carrying a movablecont act movable through manual advance of said handle, a pawl device movably mounted to said handle for limiting return movement of the handle to an intermediate position, the pawl device movable into and out of handle stopping position, means biasing said pawl device into handle stopping position, said contactor in moving to circuit open position operating said pawl device against its bias out of handle stopping position and permitting movement of the handle to the extreme position, an indicator having on and oil indicia thereon mounted to said hantile for movement therewith, means for guiding movement of said indicator relative to said handle whereby only said on indicia is viewable when said handle is in said intermediate position and only said off indicia is viewable when said handle is in said extreme position.

6. A circuit interrupter comprising a handle arranged to be advanced manually and returned automatically, means for automatically returning the handle, a stop for limiting return movement of and defining an extreme position of the handle, a contactor carrying a movable contact movable through manual advance of said handle, a pawl device movably mounted'to said handle for limiting return movement of the handle to an intermediate position, the pawl device movable into and out of handle stopping position, means biasing said pawl device into handle stopping position, said contactor in moving to circuit open position operating said pawl device against its bias out of handle stopping position and permitting movementof the handle to the extreme position, a stationary contact engageable by said movable contact, latch meansengageable with said contactor and when so engaged permitting operation of said contacts into engagement, said latch means when disengaged from said contactor preventing said contacts from remaining in and being brought into engagement, said movable contact being mounted to a first end of said contactor, said latch means being engageable with a second end of said contactor, an elongated slot and a pin one of which is stationary, said pin disposed within said slot and cooperating therewith to guide said movable contact into and out of engagement with said stationary contact.

7. A circuit interrupter comprising a handle arranged to be advanced manually and returned automatically, means for automatically returning the handle, a stop for limiting return movement of and defining an extreme position of the handle, a contactor carrying a movable contact movable through manual advance or said handle,

' apawl device movably mounted to said handle for limiting return movement of the handle to an intermediate err position, the pawl device movable into and out of handle stopping position, means biasing said pawl device into handle stopping position, said contactor in moving to circuit open position operating said pawl device against its bias out of handle stopping position and permitting movement of the handle to the extreme position, a stationary contact engageable by said movable contact, latch means engageable with said contactor and when so engaged permitting operation of said contacts intoengagement, said latch means when disenga ed from said contactor preventing said contacts from remaining in and being brought into engagement, said movable contact being mounted to a first end of said contactor, said latch means being engageable with a second end of said contactor, an elongated slot in said contactor intermediate said ends thereof, a stationary pin disposed Within said slot, said pin and said slot cooperating to guide said movable contact into and out of engagement with said stationary contact, a main spring for urging said movable contact toward engagement with said stationary contact when said contactor second end is engaged by said latch means and for urging said movable contact away from engagement'with said stationary contact after release of said contactor second end by said latch means, said main spring engaging said contactor at a point intermediate said second end and said slot.

8. A circuit interrupter comprising a handle arranged to be advanced manually and returned automatically, means for automatically returning the handle, a stop for limiting return movement of and defining an extreme position of the handle, a contactor carrying a movable contact movable through manual advance of said handle, a pawldevice movably mounted to said handle for limiting' return movement of the handle to an intermediate position, the pawl device movable into and out of handle stopping position, means biasing said pawl device into handle stopping position, said contactor in moving to circuit open position operating said pawl device against its bias out of handle stopping position and permitting movement of the handle to the extreme position, a stationary contact engageable by said movable contact, latch means engageable with said contactor and when so engaged permitting operation of said contacts into engagement, said latch means when disengaged from said contactor preventing said contacts from remaining in and being brought into engagement, said handle having a cam surface eng'ageable with a cam surface of said contactor whereby advancement of said handle from said extreme position is efiective to move said contactor into engagement with said latch means.

9. A circuit interrupter comprising a handle arranged to be advanced manually and returned automatically, means for automatically returning the handle, a stop for limiting return movement of and defining an extreme position of the handle, a contactor carrying a movable contact movable through manual advance of said handle, a pawl device movably mounted to said handle for limiting return movement of the handle to an intermediate position, the pawl device movable into and out of handle stopping position, means biasing said pawl device into handle stopping position, said contactor in moving'to circuit open position operating said pawl device against its bias out of handle stoppng position and permitting movement of the'handle to the extreme position, a stationary contact engageable by said movable contact, latch means engageable with said contactor and when so engaged permitting operation of said contacts into engagement, said latch means when disengaged from said contactor preventing said contacts from remaining in and being brought into engagement, said handle having a'cam surface engageable with a cam'surface or" said contactor whereby advancement of said handle from said extreme position is effective to move said contactor into engagement with said latch means, said movable contact being mounted to a first end of said contactor, said scrapes latch means being engageable With a second end of said contactor, an elongated slot in said contactor intermediate said ends thereof, a stationary pin disposed Within said slot, said pin and said slot cooperating to guide said movable contact into and out of engagement with said stationary contact, a main spring for urging said movable contact toward engagement with said stationary contact when said contactor second end is engaged by said latch means and for urging said movable contact away from engagement with said stationary contact after release of said contactor second end by said latch means, said main spring engaging said contactor at a point intermediate said second end and said slot.

10. A circuit interrupter comprising a handle arranged to be advanced manually and returned automatically, means for automatically returning the handle, a stop for limiting return movement of and defining an extreme position of the handle; a contactor carrying a movable contact movable through manual advance f said handle, a pawl device movably mounted to said handle for limiting return movement of the handle to an intermediate position, the pawl device movable into out of handle position, means biasing said pawl device into handle stopping position, said contactor in moving to circuit open position operating said pawl device against its bias out of handle stopping position and permitting move ment of the handle to the extreme position, a stationary contact engageable by said movable contact, latch means engageable with said contactor and when so engaged permitting operation of said contacts into engagement, said latch means when disengaged from said contactor preventing said contacts from remaining in and being brought into engagement, said pawl device having a portion engageable with. said latch means for tripping thereof upon advancement of said handle from said intermediate position while said pawl device is in said handle stopping position, a time delay tripping means comprising a bimetal element engagcable with said latch means for tripping thereof, an instantaneous fringing means comprising a coil operatively positioned to have a magnetic field generated by current flowing in said coil embrace said latch means for tripping thereof, said handle having a cam surface engageable with a cam surface of said contactor whereby advancement of said handle from said extreme position is eifective to move said contactor into engagement with said latch means.

ll. A circuit inter ugater sub-assembly comprising a frame, a contactor mounted to said frame at a first contactor pivot location; a movable contact mounted to said contactor, latch means mounted to said frame and engageablc with said contactor at a second contactor pivot location; said latch contact-or engagement being limited to corresccnd to the engagement of said movable contact with a statione contact, time delay ipping means comprising a trip, rug binietal mounted to frame normally displaced from said latch means, said bimetal when subjected to overload currents de ecting into engagement with said latch means for tripping thereof, an instantaneous tripping means comprising a coil mounted to said frame and operatively positioned to have a magnetic field generated by curr flowing in said coil embrace said latch means for topping thereof; said sub-assembly characterized as being a self-contained unit, thereby permitting electrical calibration external to an assembled circuit interrupter containing said sub-assembly.

12. A circuit interrupter 'subassembly comprising a frame, a contact-r mounted to sai' frame, latch means mounted to said frame and eugageable with said contactor, time delay tri L means comprising a tripping bimetal mounted to said frame and normally displaced from said latch means, said bimetai when subjected to overload currents deflecting into engagement with said latch means for tripping thereof, an instantaneous tripping means corn.- prising a coil mounted to said frame and operatively positioned to have a magnetic field generated by current ill flowing in said coil embrace said latch means for tripping thereof, a movable contact mounted to a first end of said contactor, said latch means being engageable with a secend end of said contact-or at a second contactor pivot location, an elongated slot in said contactor intermediate said ends thereof at a first contactor pivot location, a stationary pin extending from said frame and disposed within said slo said pin and said slot cooperating to engage said contactor an latch and correspondingly guide said movable contact into engagement with a stationary contact; said sub-assem ly characterized as being a selfcontained unit, thereby permitting electrical calibration external to an assembled circuit interrupter containing said sub-assembly.

13. A circuit interrupter sub-assembly comprising a frame, a contactor mounted to said frame, latch means mounted to said frame and engageabie with said contactor, time delay tripping means comprising a tripping bimetal mounted to said frame and normally displaced from said latch means, said bimetal when subjected to overload currents deflecting into engagement with said latch means for tripping thereof, an instantaneous tripping means comprising a coil mounted to said frame and operativeiy positioned to have a magnetic field generated by current flowing in said coil embrace said latch means for tripping thereof, a movable contact mounted to a first end of said contactor, said latch means being pivotally engageable with a second end of said contactor at a second contactor pivot location, an elongated slot in said contactor intermediate stid ends thereof at a first contactor pivot location, a stationary pin extending from said frame and disposed within said slot, said pin and said slot cooperating to engage said contactor and latch and correspondingly guide movable contact into engagement wa stationary contact, a main spring bearing against said contactor at a point intermediate said second end and said slot; said sub-assembly hracterized as being a self-contained unit, thereby permitting electrical calibration external to an assembled circuit interrupter con taining said sub-assembly.

14. A circuit interrupter sub-asseinbly comprising a frame, a contactor mounted to said frame, latch means mounted to said frame and engageable with said contactor, time delay tripping means comprising a tripping bimetal mounted to said frame and normally displaced "rem said latch means, said bimetal when subjected to overload currents deflecting into engagement with said latch means for tripping thereof, an instantaneous tripmeans comprising a coil mounted to said frame and operatively positioned to have a magnetic field generated by current flowing in said coil embrace said latch means for tripping thereof, a movable contact mounted to a first end of said contactor, said latch means being engageable with a second end of said contactor, an elongated slot in said contactor intermediate said ends thereof, a stationary pin extending from said frame and disgosed with "1 said slot, said pin said slot cooperating to guide said movable contact into and out of engagement with a stationary contact, a main spring bearing a, net said contactor at a point intermediate said second end and said clot, said latch means being pivoted to said frame and including a hooked extension cngageable by a manually operated member for tripping of said latch means.

15. A circuit interrupter sub-assembly comprising a frame, a contactor mounted to said frame at a first contactor pivot location; a movable contact mounted to said contractor, latch mounted to said frame and engageable with said contactor at a second contactor pivot location; said latch and contactor engagement being limited to correspond to the engagement of said movable contact with a stationary contact, time delay trieping means comprising a trigping bimctal mounted to said frame and normally displaced from said latch means, said bimetal when subiected to overload currents deflecting into engagement with said latch means for tripping thereso eness of, an instantaneous tripping means comprising a coil mounted to said frame and operatively positioned to have a magnetic field generated by current flowing in said coil embrace said latch means for tripping thereof, said frame having a protrusion adapted to be engaged by an operating handle carried means for restraining the handle in a predetermined intermediate position.

16. A circuit interrupter sub-assembly comprising a frame, a contactor mounted to said frame, latch means mounted to said frame and engageable with said contactor, time delay tripping means comprising a tripping bimetal mounted to said frame and normally displaced from said latch means, said bimetal when subjected to overload currents deflecting into engagement with said latch means for tripping thereof, an instantaneous tripping means comprising a coil mounted to said frame and operatively positioned to have a magnetic field generated by current flowing in said coil embrace said latch means for tripping thereof, a movable contact mounted to a first end of said contactor, said latch means being engageable with a second end of said contactor, an elongated slot in said contactor intermediate said ends thereof, a stationary pin extending from said frame and disposed within said slot, said pin and said slot cooperating to guide said movable contact into and out of engagement with a stationary contact, a main spring bearing against said contactor at a point intermediate said second end and said slot, said latch means being pivoted to said frame and including a hooked extension engageable by a manually operated member for tripping of said latch'means, biasing means urging said latch means into latching position; said frame having a protrusion adapted to be engaged by an operating handle carried means for restraining the handle in a predetermined position.

17. A circuit interrupter sub-assembly comprising a frame, a contactor mounted to said frame at a first contactor pivot location; a movable contact mounted to said contactor, latch means mounted to said frame and engageable with said contactor at a second contactor pivot location; said latch and contactor engagement being limited to correspond to the engagement of said movable contact with a stationary contact, time delay tripping means comprising a tripping bimetal mounted to said frame and normally displaced from said latch means, said bimetal when subjected to overload currents deflecting into engagement with said latch means for tripping thereof, an instantaneous tripping means comprising a coil mounted to said frame and operatively positioned to have a magnetic field generated by current flowing in said coil embrace said latch means for tripping thereof; said contactor having a cam surface engageable by an operating handle means for operation of said contactor into engagement with said latch means.

18. A circuit interrupter sub-assembly comprising a frame, a contactor mounted to said frame at a first contactor pivot location; a movable contact mounted to said c'ontactor, latch means mounted to said frame and engageable with said contactor at a second contactor pivot location; said latch and contactor engagement being limited to correspond to the engagement of said movable contact with a stationary contact, time delay tripping means com-- prising a tripping bimetal mounted to said frame and normally displaced from said latch means, said bimetal when subjected to overload currents deflecting into engagement with said latch means for tripping thereof, an instantaneous tripping means comprising a coil mounted to said frame and operatively positioned to have a magnetic field generated by current flowing in said coil embrace said latch means for tripping thereof, a temperature compensating bimetal interposed between said tripping bimetal' and said frame, said temperature compensating bimetal when heated moving said tripping bimetal away from said latch means.

'19. A circuit interrupting means comprising a molded for translational movement, an electrical sub-assembly fixedly mounted within said case, a stationary contact mounted within said case, said electrical sub-assembly including current responsive automatic tripping means and a contactor carrying a movable contact positioned to engage said stationary contact a latch means to pivotally engage said co'ntactor; said electrical sub-assembly mounted to a frame for insertion as a self-contained unit into said molded casing, thereby permitting electrical calibration of said electrical sub-assembly external to said molded casing and ubstantially independent of dimensional instability of said molded casing; said handle subassembly having a portion engageable with said contactor to effect engagement of said contactor and latch for operation of said contacts into engagement.

20. A circuit interrupting means comprising a molded casing, a handle sub-assembly mounted Within said casing for translational movement, an electrical sub-assembly fixedly mounted within said case, a stationary contact mounted within said case, said electrical subassembly comprising a frame, a contactor mounted to said frame, latch means mounted to said frame and pivotally engageable with said contactor, time delay tripping means comprising a tripping bimetal. mounted to said frame and normally displaced from said latch means, bimetal when subjected to overload currents deflecting into engagement with said latch means for tripping thereof, an instantaneous tripping means comprising a coil mounted to said frame and operatively positioned to have a magnetic field generated by current flowing in said coil embrace said latch means for tripping thereof, said handle sub-assembly including a portion engageable with said contactor to effect engagement of said contactor and latch for operation of said contacts into engagement.

21. A. circuit interrupting means comprising a molded casing, a handle sub-assembly mounted within said casing for translational movement, an electrical sub-assembly fixedly mounted within said case, a stationary contact mounted within said case, said electrical sub-assembly including a contactor carrying a movable contact positioned to engage said stationary contact, said handle subassembly comprising a handle and a pawl device pivotally mounted to said handle, said handle arranged to be advanced manually and returned automatically, means for automatically returning the handle, a stop for limiting return movement of and defining an extreme position of the handle, said pawl device limiting return movement of the handle to an intermediate position, the pawl device movable into and out of handle stopping position, means biasing said pawl device into handle stopping position, said contactor in moving to circuit open position operatmg saidpawl device against its bias out of handle stopping position and permitting movement of the handle to the extreme position.

22. A circuit interrupting means comprising a molded casing, a handle-sub-assembly mounted within said casing for translational movement, an electrical sub-assembly fixedly mounted within said case, a stationary contact mounted within said case, said electrical sub-assembly including a contactor carrying a movable contact positioned to engage said stationaryrcontact, said handle subassembly comprising a handle and a pawl device pivotally mounted to said handle, said handle arranged to be advanced manually and returned automatically, means for automatically returning the handle, a stop for limiting return movement of and defining an extreme position of the handle, said pawl device limiting return movement of the handle to an intermediate position, the pawl device movable into and out of handle stopping position, means biasing said pawl device into handle stopping position, said contactor in moving to circuit open position operating said pawl device against its bias out of handle stopping position and permitting movement of the handle to the extreme position, latch means engageable with said contactor and when so engaged permitting operation of said contacts into engagement, said latch means when disengaged from said contactor preventing said contacts from remaining in and being brought into engagement, said pawl device having a portion engageable with said latch means for tripping thereof upon advancement of said handle from said intermediate position while said pawl device is in said handle stopping position.

23. A circuit interrupting means comprising a molded casing, a handle sub-assembly mounted within said casing for translational movement, an electrical sub-assembly fixedly mounted within said case, a stationary contact mounted within said case, said electrical sub-assembly including a contactor carrying a movable contact positioned to engage said stationary contact, said handle sub-assembly comprising a handle and a pawl device pivotally mounted to said handle, said handle arranged to be advanced manually and returned automatically, means for automatically returning the handle, a stop for limiting return movement of and defining an extreme position of the handle, said pawl device limiting return movement of the handle to an intermediate position, the pawl device movable into and out of handle stopping position, means biasing said pawl device into handle stopping position, said contactor in moving to circuit open position operating said pawl device against its bias out of handle stopping position and permitting movement of the handle to the extreme position, latch means engageable with said contactor and when so engaged permitting operation of said contacts into engagement, said latch means when disengaged firom said contactor preventing said contacts from remaining in and being brough into engagement, said pawl device having a portion engageable with said latch means for tripping thereof upon advancement of said handle from said intermediate position while said pawl device is in said handle stopping position, an indicator having on and off indicia thereon mounted to said handle for operation therewith, said indicator having an extension extending into a groove of said case constructed to guide movement of said indicator relative to said handle whereby only said on indicia is viewable when said handle is in said intermediate position and only said off indicia is vewable when said handle is in said extreme position.

24. A circuit interrupter comprising a pair of cooperating contacts, a contactor carrying a first of said coopcrating contacts, first means operatively engageable with said contactor for operation of said cooper-ating contacts into engagement, latch means for maintaining a portion of said contactor in an operative position such that advancement of said first means is effective to bring about engagement of said cooperating contacts only when said latch means maintains the portion of the contactor in said operative position, a pivot for said contactor, said pivot being positioned intermediate the ends of said contactor, said first cooperating contact being positioned on one side of said pivot and said latch means engageable with said contactor on the other side of said pivot, said first means having a part engageable with said latch means for tripping thereof upon advancement of said first means when said cooperating contacts are in engagement.

25. A circuit interrupter comprising a pair of cooperating contacts, a contactor carrying a first of said cooperating contacts, first means operatively engageable with said contactor for operation of said cooperating contacts into engagement, latch means for maintaining a portion of said contactor in an operative position such that operation of said first means is efiective to bring about engagement of said cooperating contacts only when said latch means maintains the portion of the contactor in said operative position, a pivot for said contactor, said pivot being positioned intermediate the ends of said contactor, a slot for journaling movement of said contactor relative to said pivot, said first cooperating contact being positioned on one Side of said pivot and said latch means engageable with said contactor on the other side of said pivot, said first means having a part engageable with said latch means for tripping thereof upon advancement of said first means when said cooperating contacts are in engagement.

References Cited in the file of this patent UNITED STATES PATENTS 1,952,040 Frank et a1. Mar. 20, 1934 2,3 85,727 Platz Sept. 25, 1945 2,539,567 Best Jan. 30, 1951 2,611,052 Platz et al. Sept. 16, 1952 2,656,437 Allen Oct. 20, 1953 2,696,541 Habermann Dec. 7, 1954 2,816,192 Ingwersen Dec. 10, 1957 2,847,533 Christensen Aug. 12, 1958 2,863,023 Rowe Dec. 2, 1958 2,887,548 Middendorf May 19, 1959 2,895,028 Ellenberger July 14, 1959 2,938,983 Thomas May 31, 1960 

1. A CIRCUIT INTERRUPTER COMPRISING A HANDLE ARRANGED TO BE ADVANCED MANUALLY AND RETURNED AUTOMATICALLY, MEANS FOR AUTOMATICALLY RETURNING THE HANDLE, A STOP FOR LIMITING RETURN MOVEMENT OF AND DEFINING AN EXTREME POSITION OF THE HANDLE; A CONTACTOR CARRYING A MOVABLE CONTACT MOVABLE THROUGH MANUAL ADVANCE OF SAID HANDLE, A PAWL DEVICE MOVABLY MOUNTED TO SAID HANDLE FOR LIMITING RETURN MOVEMENT OF THE HANDLE TO AN INTERMEDIATE POSITION, THE PAWL DEVICE MOVABLE INTO AND OUT OF HANDLE STOPPING POSITION, MEANS BIASING SAID PAWL DEVICE INTO HANDLE STOPPING POSITION, SAID CONTACTOR IN MOVING TO CIRCUIT OPEN POSITION OPERATING SAID PAWL DEVICE AGAINST ITS BIAS OUT OF HANDLE STOPPING POSITION AND PERMITTING MOVEMENT OF THE HANDLE TO THE EXTREME POSITION. 